Is Paradise Lake Polluted?
Yes — Paradise Lake in Coles County, Illinois is on the EPA's Clean Water Act 303(d) impaired-waters list (2024 assessment cycle). It is cited for Algal growth, Mercury, Metals (other than mercury), Nutrients (phosphorus, nitrogen), Oxygen depletion (low DO), pH / acidity, Turbidity. A formal cleanup plan — a Total Maximum Daily Load (TMDL) — has been written. "Impaired" is a legal designation, separate from the lake's A–F water-quality grade: it means at least one designated use (such as swimming, aquatic life, or fish consumption) does not meet state standards for the listed pollutant.
EPA 303(d) Listing
| On 303(d) impaired list | Yes |
| Cleanup plan (TMDL) | Completed |
| Assessment cycle | 2024 |
| EPA IR category | 5 |
| Location | Coles County, Illinois |
Pollutants Cited
- Algal growth — listed by EPA as exceeding water-quality standards for at least one designated use.
- Mercury — Mercury accumulates in fish tissue and is the single most common impairment in northern lakes. It usually arrives via atmospheric deposition from coal combustion rather than local discharge — which is why even remote, clear lakes can be mercury-impaired. It triggers fish-consumption advisories, not swimming closures.
- Metals (other than mercury) — listed by EPA as exceeding water-quality standards for at least one designated use.
- Nutrients (phosphorus, nitrogen) — Excess phosphorus and nitrogen fuel algae growth and summer blooms. This is the classic agricultural-runoff and shoreline-development impairment, and the one most likely to affect swimming via blue-green algae.
- Oxygen depletion (low DO) — listed by EPA as exceeding water-quality standards for at least one designated use.
- pH / acidity — listed by EPA as exceeding water-quality standards for at least one designated use.
- Turbidity — listed by EPA as exceeding water-quality standards for at least one designated use.
Specific parameters in the EPA record: ALGAE, DISSOLVED OXYGEN, IRON, MERCURY, PH, PHOSPHORUS, TOTAL, TOTAL SUSPENDED SOLIDS (TSS), TURBIDITY.
What this means for using Paradise Lake
Because Paradise Lake is listed for Nutrients (phosphorus, nitrogen), swimming can be affected — check for posted beach advisories, especially after heavy rain or during visible algae. An impairment listing does not mean the lake is closed — most impaired lakes remain open for boating and swimming. It means a specific pollutant exceeds a standard for a specific use. Paradise Lake carries an overall water-quality grade of F and phosphorus at 139 µg/L — see the full breakdown on the lake report. The official EPA assessment is available in the ATTAINS waterbody report.